Beyond the Fog Lies Clarity
by gracetheworld
Summary: A half-youkai son and a completely human daughter, his twin children that Rihan loved with his whole heart, and it was because he loved them so that he was worried of their fates that were waiting them up ahead, for their fates had been decided for them since the world was created. AU, OC. Set in the merged universe of Nura Mago and SMT's Devil Survivor.


**Beyond the Fog Lies Clarity**

 _By gracetheworld_

 _A half-youkai son and a completely human daughter, his twin children that Rihan loved with his whole heart, and it was because he loved them so that he was worried of their fates that were waiting them up ahead, for their fates had been decided for them since the world was created._

 **Nurarihyon no Mago belongs to Shiibashi Hiroshi-Sensei and Devil Survivor belongs to ATLUS. I only own Nao.**

* * *

 **Prologue**

After a long, grueling night of tense atmosphere, the people of the main house of the Nura Clan rejoiced at the birth of the new heir, or rather heirs. Nura Wakana had unexpectedly carried twins instead of just one baby (a big one, seeing how big the bulge on her stomach was), so when the births occurred, it became a surprise to the yokais of the main house, though it wasn't an unwelcomed one.

The babies were born without any complication. However, even from their birth, they were a stark contrast to one and another. Everyone who laid their eyes upon the two tiny babies would notice that in an instant.

Nura Rikuo, the younger of the twins by three minutes, was like any other baby who cried as soon as he was born. However, much to the clan's, especially the twin's father's surprise, for someone who was supposed to be only _one quarter_ yokai, Rikuo felt more like a _half_ rather than a mere quarter.

His older twin sister, Nura Nao, on the other hand, was quiet when she got out of her mother's womb, with not a single cry escaping her lips that night. If it weren't for the fact that she breathed just fine and she constantly move her arms and legs, everyone would have thought that she was dead. Moreover, if Rikuo seemed to be more yokai than he should have been, then Nao seemed to be completely human, without even a trace of yokai power in her.

After telling this to his father, Rihan received a thoughtful response from the older yokai. "Well… there has never been a female born to our line. Then again, it might have just been that her yokai power has not manifested yet, though that wouldn't make much sense, since Rikuo seems to have a lot of them, even if he had just been born." Nurarihyon stroked his chin thoughtfully, glancing at both of his grandchildren. "Or maybe, as outrageous and impossible as it might be, maybe in some complicated and unconscious kind of way, Nao had given up her yokai side and gave it to Rikuo while they were both in womb, which would explain why Rikuo feels more like a Hanyo than a quarter yokai, and why Nao feels like a human instead of a quarter yokai. Either way, right now, Nao isn't showing any signs of yokai power."

Maybe it was his paternal instincts, maybe it was something else, but Rihan had a feeling that it was more the third option rather than the other two. Twin yokais were rare after all, in fact they were almost unheard of, especially mixed blood like Nao and Rikuo were, so it might have been possible for that sort of thing to happen. There was no sure way for them to know what really happened, and they could only see how the future would progress with something like this.

If that was really what happened though, it made Rihan think that his daughter, even in womb, had understood how hard it would be to live as a quarter yokai, especially by the upper echelons that were made up of the more traditional yokai. Moreover, it seemed like she knew how _Rikuo_ would be looked down because he was the male heir (meaning more expectations), and wanted to make things easier for her younger twin, thus why she gave up her yokai power to her younger twin.

As impossible as it was, but they were yokai, they should expect the impossible to happen sometimes.

A fond smile stretched Rihan's lips. "Either way, whether she's yokai or human, she's still my daughter, and if nobody can accept that, then to hell with them! I will protect her and Rikuo." Rihan vowed, gently caressing his daughter's soft cheek.

His words received a coo from Rikuo, as if the younger boy agreed with his father's words. Wakana giggled in agreement at her husband's words, while his father had a smug smirk on his face. "Well said, son. Well said." The elder yokai commented.

* * *

Nao(1) had always seemed to act older than she looked; more mature than a child her age should be. Her eyes seemed to look so old, as if the little brunette had seen many and _many_ things—things that children like her shouldn't have seen. Suffice to say, if this wasn't a yokai household, people around her would be unnerved by her personality. However, it did cause a little bit of an uproar in her kindergarten class, as she was too mature for the other children.

Thankfully, much to the delight of the kindergarten teachers, her mature like attitude would (somewhat) disappear when she was with her more outgoing younger twin, Rikuo. She would instantly act more childlike whenever he was around, which was almost every time, as the two were rarely separated.

Though, the attachment the girl had towards her brother (and in reverse, Rikuo's own attachment to her as well) was a bit worrying to the teachers, since it was bordering on 'brother complex'. It was nice that the two get along very well, but to be so attached at the hips and be so overprotective of her brother (and Rikuo to her)?

Well, the teachers could only hope that they'd outgrow this overprotective phase when they grew up.

* * *

The twins were six when they and their father met a girl with long black hair in their kerria flower garden. The girl had called their father 'father' too, which confused Rikuo slightly since he didn't know he had another sibling besides Nao. Much to his surprise though, after a small hesitance, their father smiled and asked if she wanted to join them to spend time in their kerria flower garden.

Shrugging his surprise aside, Rikuo looked around in excitement, eyes glimmering with excitement as he took in the beautiful view of the beautiful kerria flowers in full bloom. "Otou-san, one-san, Nacchan! Look! The flowers are so beautiful!" The brunet gestured to the flowers animatedly. "Ah, look over there! Nacchan, let's go there!"

Nao smiled slightly, though it didn't seem to reach her eyes. Ever since they met the black haired girl, Nao had seemed a little bit uneasy. It was why Rikuo wanted to show her what he saw, to get whatever was bothering Nao off her mind, even if only for a bit. Nao though, had other plan it seemed. "Rikkun, you go first. I'll catch up with you later. I still want to look around here." She urged.

Rikuo frowned for a moment, casting an unsure look at his twin sister. Still, he knew that is his twin sister wanted to stay for a bit, it must have been because of a reason. Nao never did things without a reason, after all, and so, he agreed and went first.

It had only been three minutes since he left when he heard Nao's scream. Dread filled him at that exact moment as he turned his heels and ran back to where his twin sister and father were, only to set sight on their father, their _strong and powerful_ father, lying on the ground, bleeding, as his sister knelt behind their father's body, her hands emitting a golden glow upon the wound, looking very desperate. What took the icing on the cake though was the girl that had been with them, holding a bloodied sword, her expression torn between hysteric and being cruel.

When the girl raised the bloodied sword, though, Rikuo felt the blood rushing through his veins boiled. In a blurry moment, he found himself standing protectively in front of their father and Nao, a katana (his father's katana) on his hand, blocking the girl's sword from hurting Nao.

It was somewhat a hazy feeling, what with the boiling blood rushing through his vein, but he felt his body changed. Though what made the feeling even hazier was the rushing _memories of so long ago that he shouldn't have remembered yet, but for some odd yet not unwanted reason did._

And then, as the memories ended, everything seemed clear to him, as if the fog clouding his vision had cleared, leaving behind clarity. Still, there was a more pressing matter to attend at the moment. "Nacchan," he was surprised at the fact that he wasn't surprised his voice had changed, if only slightly. His body had changed, after all. He had transformed into his yokai form. "Nacchan! Concentrate on healing oyaji. I'll protect you two."

"Rikkun…" it was rare to hear Nao so surprised, she rarely ever was. Rikuo never knew before how Nao was rarely ever surprised, but now—now that he had those memories back, he understood why. It was hard to be surprised if you've had thousands of year worth of memories from the many past lives you had lived and could never forget, after all.

"After all, not only am I going to be the Lord of all Yokai in the future, but I'm also going to be the Overlord of the demons worldwide—isn't that right, Nacchan?" His asked, smirking confidently, though his eyes never once left the black haired girl in front of him.

Rikuo didn't wait for a response from Nao as he pushed the girl's sword back. Not waiting for another attack to strike, he rushed and attacked, only for his sword to be parried by the girl. The assailant leapt backwards soon after, seemingly having settled her own internal conflict. "Che, not only his son, his grandchildren are as annoying as he was." The girl seemed to have completely changed her tone from the girl they met just minutes ago.

 _(Maybe she was. Maybe the girl from before was possessed by an unknown entity, and it was that unknown entity that attacked their father.)_

"I will be back soon." The being vowed, before she disappeared from their sight.

Sheathing the sword, Rikuo turned back to where Nao and their father were. His older twin seemed relieved, and their father didn't look completely in pain anymore, meaning that Nao had managed to save him in time.

The brunette looked up at him, her golden brown eyes staring straight into his crimson ones. "You've remembered." It wasn't even a question, just a plain statement. Then again, ever since lifetimes ago, Nao (who had bore many, _many names_ before) was never the type to ask questions with obvious answers. "How? You shouldn't have. Not until all the pieces are gathered!"

The yokai shrugged nonchalantly. "It's your memories, I think. When you gave me your yokai side back before we were born, that part of you seemed to have carried the memories of your lives as well—at least an impression of them, but it was enough to break the lock on _my_ memories." He said. The silver haired boy sat beside his brunette twin, pulling her into a hug. "You've lived lonely lives for so long, haven't you, Nacchan?" his voice was low and quiet. "Don't worry. From now on, I'll always be by your side."

In a rare act of weakness, after a small pause, Nao gave in to her feelings and hugged him back. "I killed you. So why…?"

"You are my sister. I'll always forgive you for whatever you've done wrong." He flashed her a small smile. "It was not your fault, anyways." At the memory of _that day_ , Rikuo's blood boiled some more. "I promise, Nao—once I become the Lord of Pandemonium as well as the Overlord of the demons worldwide, I will destroy that person who ruined our lives, him and his followers, once and for all."

Nao was about to respond when the gates to the garden were slammed open and the two heard frantic footsteps running to their place. "Rihan-sama! Rikuo-sama! Nao-sama!" amongst the voices calling for them, Kubinashi seemed to be the loudest.

They turned, only to see their father's closest attendants plus Yuki-Onna looking very worried. That worry turned into downright panic when they saw Rihan lying on his own pool of blood. "Ri-Rihan-sama?!" Yuki-Onna screamed, her already snow white skin had somehow looked even paler than usual, as impossible as it was.

"Oyaji is alright, Yuki-Onna. Nacchan healed him. He's just recuperating right now." Rikuo cut in before the yokai fell into more disarray than they already did. "For yokai, you guys panic way too much." There was a tone of disapproval in his voice.

"Who the hell are you?!" Aotabou asked aghast, confused and offended by the words and the tone used by the unfamiliar looking yokai brat.

"That;s Rikkun." Nao butted in, saying it so blandly as if it was the most obvious thing in the world, though if one were to know her so well, you could hear and see the hint of amusement in both her tone as well as the glint on her golden brown eyes. "Honestly, from wherever you look, he's completely a Nurarihyon, and he wears the same clothes Rikkun did since this morning."

It was a sound argument.

It broke the yokai nonetheless. "EH?!"

* * *

When Rihan came into consciousness, he was greeted by his wife's relieved face. He noticed that her eyes were red rimmed. She must have been crying a lot. Why was she crying? Did something bad happen? For some reason, he felt guilty. "Rihan-san, you're finally awake!"

The last thing he remembered was being stabbed by the girl that looked so much like Otome, and his daughter's panicking face in the place of her usual stoic expression. Instantly, he sat up, only to wince slightly at the phantom pain he felt on his chest, which was weird because even if somehow, he was saved on time, he should have felt more pain than he did just now. Still, that wasn't his biggest concern right now. "Nao! Where's Nao?! And Rikuo?!"

Wakana giggled. "Don't worry. They are fine. No scratches on them." She assured her husband. "They saved you, you know? The both of them did. Nao-chan seems to have inherited your healing ability, and Rikuo transformed into yokai to protect you two while Nao-chan healed you."

It took a few seconds for Rihan to digest what Wakana had said. "Wh…"

With another giggle, Wakana turned to the shoji door. "Children, your father is awake!"

The shoji door slid open, and two quick blurs rushed in to the man's side. "Oyaji!" "Otou-san!" Rihan's amber eyes softened when he saw Nao's concerned face, an expression his daughter rarely make. When his eyes shifted to the figure next to her though, his eyes widened.

That silver and black, gravity defying hair; the sharp, crimson red eyes; a body that was bigger than before—"Oi, Rikuo, why do you look more like oyaji than me?!"

His question received a light glare from the younger hanyo in reply. "… That is your first question, really?" Rikuo added a raised eyebrow in the mixture to relay how exasperated he was feeling right now to the older hanyo for his completely ridiculous question.

"Now, Rikkun, you can't fault otou-san on that. You do look like ojii-chan did in his younger days more than you do otou-san." Nao replied, now her concerned face gone, replaced with her usual stoic expression. "Though, with an idiotic question like that, it just means that otou-san is perfectly fine right now."

"Wakana-chan! Our children are being mean to me!" Rihan whined, turning to his wife and hugged her childishly as he pouted at his children. Only Rihan could pull of such a look despite being a grown up.

Wakana let out a small laugh at that. Nao didn't laugh outright, though her lips did twitch upward, as if she was refraining herself from laughing out loud. Rikuo let out a snicker, trying to keep the cool image he had going on.

At the sight of his family being happy, Rihan couldn't help but join in in their happiness, letting out a small laugh of his own.

That day though was the start of everything that went wrong in their lives.

* * *

 **To Be Continued**

* * *

 **Author** **'** **s Note**

 _Originally, I wanted to write a story where Day!Rikuo and Night!Rikuo are different people, however, as I tried to imagine the very situation itself, I find it hard for myself to consider them different people, because in my mind, I_ _'_ _ve always think of them as one and the same, and Night!Rikuo wasn_ _'_ _t just the manisfestation of Rikuo_ _'_ _s side, but a representation of Rikuo_ _'_ _s deepest desires. I know some people think differently to me, considering them as two different people, but I really can_ _'_ _t get myself to think and write that way._

 _Thus, the OC was born. This will be my first time actually writing an OC for a fandom that doesn_ _'_ _t serve as a villain. I_ _'_ _ve written my fair share of OCs, but they are for my original stories, thus I was free in creating them (within measures, of course), so I think that this will be a good practise for me in writing Ocs with many restrictions, as I have to conform to the rules of both the Nurarihyon no Mago universe and the Devil Survivor universe._

 _Also, I might have stated that it_ _'_ _s a Nura Mago crossover with Devil Survivor, but really, it_ _'_ _s more like it_ _'_ _s a story in Nura Mago crossover with a_ _ **lot**_ _of Devil Survivor elements. No prior knowledge of the game required, so don't worry. No_ _ **main**_ _characters of Devil Survivor will appear in this fic, with the exception of Cain and Abel, who are_ _ **not**_ _going to be Naoya and Kazuya respectively, and the angels and demons who are going to appear_ _ **much**_ _later. As you can guess, the role of Cain and Abel fell to Nao and Rikuo respectively. This is one of the main reason why I didn_ _'_ _t put this fic into the crossover archive, and instead posted this on the main one._

 _I_ _'_ _ve always been fascinated with mythologies from_ _ **many**_ _parts of the world, and I wanted to try blend them into a fic. As this is a Nura Mago fic, I_ _'_ _m still going to focus more on yokai rather than the other pantheon_ _'_ _s mythical beings, but in the future, other pantheons, especially the Judeo-Christian (as_ _ **that**_ _was what Devil Survivor was heavily based on), will effect the story more and more._

 _That all being said, I am really hoping that this will be a decent fic with a likeable OC. I_ _'_ _ll try not to make her a Mary Sue._

 _Well_ _—_ _that_ _'_ _s a really long author_ _'_ _s note. I hope you enjoy the fic, thank you so much for actually taking time to read this!_

* * *

 **Additional Note:**

(1) Nao's name uses the kanji 尚 meaning furthermore; still more; greater. I think it's a perfect name for her because as you can already see from this prologue, there are a lot more to Nao.

(Fun fact! Alternatively, her name could have used the kanji 直, which has the same reading [nao] but meaning ordinary, which to the point of view of the yokai of the Nura Clan, especially the upper echelon, was what she was. This would probably appear in the future chapters.)


End file.
